Single-phase autotransformer wire end alternating current induction voltage withstanding test method

Abstract

The invention relates to a single-phase autotransformer wire end alternating current induction voltage withstand test method, which is characterized in that an intermediate transformer is used for replacing a support transformer in a traditional test method, an intermediate frequency generator, a compensation reactor, an intermediate transformer T1 and an intermediate transformer T2 are sequentially connected, and the intermediate transformer T2 is connected with a tested single-phase autotransformer. According to the test system, a support transformer is omitted, so that the design of the test system is simpler; testing is achieved through the intermediate transformer T2, the phenomenon that the polarity of the intermediate transformer and the polarity of the supporting transformer are opposite and the supporting vectors are opposite is avoided, and the phase angle difference generated due to different parameters such as capacity and impedance of the intermediate transformer and the supporting transformer is avoided. The excitation modes are different, so that the change of the inlet capacitance is not large when the voltage is corrected, and the self-excitation risk of the generator is avoided; after the voltage correction is completed, the voltage divider is removed, the capacitance rise coefficient is changed, and the voltage correction is more accurate compared with a traditional mode.

Description

technical field [0001] The invention belongs to the technical field of transformer testing and testing, and in particular relates to a new method for AC induction withstand voltage testing of line terminals of a single-phase autotransformer. Background technique [0002] The entire power grid system is divided into four links: power generation, power transmission, power distribution, and power consumption. Among them, power transformers are used in the first three links, so transformers are crucial electrical equipment in power systems. The safe operation of the transformer is the key to the safe operation of the power grid. In order to prevent and detect the insulation defects inside the electrical equipment, the main primary equipment such as the transformer must undergo a factory test before leaving the factory. It is very important that the AC induction withstand voltage test is the most effective and direct method to identify the insulation strength of electrical equipm...

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Problems solved by technology

[0003] In the traditional single-phase autotransformer line-side AC induction withstand voltage test method, the intermediate transformer and the supporting transformer are used. Although the power supply of the intermediate transformer and the supporting transformer is the same power supply, the angular difference, capacity rise, etc. Different, the head-end voltage correction must be performed when conducting the line-end induced voltage test; the intermediate transformer and the supporting transformer have different parameters such as capacity and impedance, and there is a greater possibility of insufficient reactive power compensation, which increases the risk of generator self-excitation; the test When the voltage divider is removed, the capacity rise becomes smaller, so the voltage correction deviation is large, and the test voltage is prone to deviation; the polarity of the supporting transformer and the intermediate transformer may be opposite during the test, and the voltage of the medium voltage to the neutral point may be too high during the test. Risk of insulation breakdown between turns

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